diff --git a/docs/api/request.md b/docs/api/request.md index 8fdaa2f..196e326 100644 --- a/docs/api/request.md +++ b/docs/api/request.md @@ -186,19 +186,26 @@ if (this.is('image/*')) { } ``` +### Content Negotiation + + Koa's `request` object includes helpful content negotiation utilities powered by [accepts](http://github.com/expressjs/accepts) and [negotiator](https://github.com/federomero/negotiator). These utilities are: + +- `req.accepts(types)` +- `req.acceptsEncodings(types)` +- `req.acceptsCharsets(charsets)` +- `req.acceptsLanguages(langs)` + + If no types are supplied, __all__ acceptable types are returned. + + If multiple types are supplied, the best match will be returned. If no matches are found, a `false` is returned, and you should send a `406 "Not Acceptable"` response to the client. + + In the case of missing accept headers where any type is acceptable, the first type will be returned. Thus, the order of types you supply is important. + ### req.accepts(types) - Check if the given `type(s)` is acceptable, returning - the best match when true, otherwise `false`, in which - case you should respond with 406 "Not Acceptable". - - The `type` value may be one or more mime type string + Check if the given `type(s)` is acceptable, returning the best match when true, otherwise `false`. The `type` value may be one or more mime type string such as "application/json", the extension name such as "json", or an array `["json", "html", "text/plain"]`. - When a list or array is given the _best_ match, if any is returned. - - Note that if the client did not send an `Accept` header, - the first `type` will be returned. ```js // Accept: text/html @@ -218,12 +225,18 @@ this.accepts('application/json'); // Accept: text/*, application/json this.accepts('image/png'); this.accepts('png'); -// => undefined +// => false // Accept: text/*;q=.5, application/json this.accepts(['html', 'json']); this.accepts('html', 'json'); // => "json" + +// No Accept header +this.accepts('html', 'json'); +// => "html" +this.accepts('json', 'html'); +// => "json" ``` You may call `this.accepts()` as may times as you like, @@ -234,21 +247,20 @@ switch (this.accepts('json', 'html', 'text')) { case 'json': break; case 'html': break; case 'text': break; - default: this.throw(406); + default: this.throw(406, 'json, html, or text only'); } ``` ### req.acceptsEncodings(encodings) - Check if `encodings` are acceptable, returning - the best match when true, otherwise `identity`. + Check if `encodings` are acceptable, returning the best match when true, otherwise `false`. Note that you should include `identity` as one of the encodings! ```js // Accept-Encoding: gzip -this.acceptsEncodings('gzip', 'deflate'); +this.acceptsEncodings('gzip', 'deflate', 'identity'); // => "gzip" -this.acceptsEncodings(['gzip', 'deflate']); +this.acceptsEncodings(['gzip', 'deflate', 'identity']); // => "gzip" ``` @@ -258,13 +270,15 @@ this.acceptsEncodings(['gzip', 'deflate']); ```js // Accept-Encoding: gzip, deflate this.acceptsEncodings(); -// => ["gzip", "deflate"] +// => ["gzip", "deflate", "identity"] ``` + Note that the `identity` encoding (which means no encoding) could be unacceptable if the client explicitly sends `identity;q=0`. Although this is an edge case, you should still handle the case where this method returns `false`. + ### req.acceptsCharsets(charsets) Check if `charsets` are acceptable, returning - the best match when true, otherwise `undefined`. + the best match when true, otherwise `false`. ```js // Accept-Charset: utf-8, iso-8859-1;q=0.2, utf-7;q=0.5 @@ -287,7 +301,7 @@ this.acceptsCharsets(); ### req.acceptsLanguages(langs) Check if `langs` are acceptable, returning - the best match when true, otherwise `undefined`. + the best match when true, otherwise `false`. ```js // Accept-Language: en;q=0.8, es, pt diff --git a/test/request/acceptsEncodings.js b/test/request/acceptsEncodings.js index 0cdc189..9a64e70 100644 --- a/test/request/acceptsEncodings.js +++ b/test/request/acceptsEncodings.js @@ -16,7 +16,7 @@ describe('ctx.acceptsEncodings()', function(){ it('should return identity', function(){ var ctx = context(); ctx.acceptsEncodings().should.eql(['identity']); - ctx.acceptsEncodings('gzip', 'deflate').should.equal('identity'); + ctx.acceptsEncodings('gzip', 'deflate', 'identity').should.equal('identity'); }) }) })